Biomaterial Database

FAR1 is required for oriented polarization of yeast cells in response to mating pheromones. 1995

N Valtz, and M Peter, and I Herskowitz

Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448, USA.

Cell polarization involves specifying an area on the cell surface and organizing the cytoskeleton towards that landmark. The mechanisms by which external signals are translated into internal landmarks for polarization are poorly understood. The yeast Saccharomyces cerevisiae exhibits polarized growth during mating: the actin cytoskeleton of each cell polarizes towards its partner, presumably to allow efficient cell fusion. The external signal which determines the landmark for polarization is thought to be a gradient of peptide pheromone released by the mating partner. Here we described mutants that exhibit random polarization. Using two assays, including a direct microscope assay for orientation (Segall, J. 1993. Proc. Natl. Acad. Sci. USA. 90:8332-8337), we show that these mutants cannot locate the source of a pheromone gradient although they are able to organize their cytoskeleton. These mutants appear to be defective in mating because they are unable to locate the mating partner. They carry mutations of the FAR1 gene, denoted far1-s, and identify a new function for the Far1 protein. Its other known function is to promote cell cycle arrest during mating by inhibiting a cyclin-dependent kinase (Peter, M., and I. Herskowitz. 1994. Science (Wash. DC). 265:1228-1232). The far1-s mutants exhibit normal cell cycle arrest in response to pheromone, which suggests that Far1 protein plays two distinct roles in mating: one in cell cycle arrest and the other in orientation towards the mating partner.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010675	Pheromones	Chemical substances, excreted by an organism into the environment, that elicit behavioral or physiological responses from other organisms of the same species. Perception of these chemical signals may be olfactory or by contact.	Allelochemical,Allelochemicals,Allomone,Allomones,Ectohormones,Kairomone,Kairomones,Pheromone,Semiochemical,Semiochemicals,Synomones
D012097	Repressor Proteins	Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.	Repressor Molecules,Transcriptional Silencing Factors,Proteins, Repressor,Silencing Factors, Transcriptional
D002453	Cell Cycle	The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.	Cell Division Cycle,Cell Cycles,Cell Division Cycles,Cycle, Cell,Cycle, Cell Division,Cycles, Cell,Cycles, Cell Division,Division Cycle, Cell,Division Cycles, Cell
D005656	Fungal Proteins	Proteins found in any species of fungus.	Fungal Gene Products,Fungal Gene Proteins,Fungal Peptides,Gene Products, Fungal,Yeast Proteins,Gene Proteins, Fungal,Peptides, Fungal,Proteins, Fungal
D005800	Genes, Fungal	The functional hereditary units of FUNGI.	Fungal Genes,Fungal Gene,Gene, Fungal
D005816	Genetic Complementation Test	A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.	Allelism Test,Cis Test,Cis-Trans Test,Complementation Test,Trans Test,Allelism Tests,Cis Tests,Cis Trans Test,Cis-Trans Tests,Complementation Test, Genetic,Complementation Tests,Complementation Tests, Genetic,Genetic Complementation Tests,Trans Tests
D000483	Alleles	Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.	Allelomorphs,Allele,Allelomorph
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D016764	Cell Polarity	Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.	Cell Polarities,Polarities, Cell,Polarity, Cell